Speedjerry, I did some of the original testing of 5.56 vs. 9mm on interior walls a long time ago. Fired from 10 feet into two sides of sheetrock, separated by 2 X 4, 10' beyond another identical wall, 10' beyond that was a wall, one side sheetrock, one side T10 siding.
All 9mm rounds from a handgun went through all walls. 5.56/223 rounds all went through the first wall, some made it through the 2nd wall, none made it through the last wall. This included 5.56 green tip AP, fired from a Styer AUG. (9mm was the only round I tested, it was fired from a BHP)
The 9mm rounds penetrate by mass, the 5.56/.223 by velocity. Rounds loose velocity on impact, not mass.
And, as noted your particular living situation defines what may be best. I have a two MILE field of fire .... err, field of view, so I can use my full auto BAR if the situation calls for it.
Bedroom long gun - M4gery w/55g JHP
If outdoors, Win M94 in .44Mag - Why? puts down coyotes, if needed against an outlaw, "sells" much better in court than the M4 to solve "problem 2". Both get exercised regularly, along with our handguns.